SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14e66fcf5daafb92c4986ffce1986237d2b1c597c88eec2c7b3c08cb0d224c43' 
  AND token = 'tg/20Hvt5lhH9CajKgt3zPFrqPQklEf4ywmOJmMsz+w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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