SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f479d676df3cde050b822b2bb471571b15505acf43093a8c73bee23091f6ec89' 
  AND token = 'ELpCMWaoGjU/en0Tnnx/HGEgzhAt3MxYuik4dlXfjB4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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