SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f03f10c3aa0b87bdb09f2311057052b101dd71846a5d5f2c44764952128f3896' 
  AND token = 'VqU8Y6YC13WIGNPsHaZAJ6x9nSrA5uRDj/Zl2dVt8HU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}