SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed8d75268b088eadfa67bd2f07afa15f7b64776a50c73b4b8c49e472c3eeb214' 
  AND token = 'Fm20Zo6Bacb4RwYgLx2P1YIwA9fDEXTgAQki8KvqgVI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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