SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48c5624eb0e34a3331c5441a35319339c69fddef1bb0607bad01ae911d0837a2' 
  AND token = 'i6gfM0OgIf2m5Yi7ziaFaR6iWcuSD06mo9EjgnzWJ4E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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