SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'daeb368ac9a65da54ee536814d0cfc8ef725903f882210085fda0dbf9b9d395b' 
  AND token = '31INvGsal63blgHYi7kWD4USbWiYc22Q8C3vgVhPgcw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}