SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9e36c05b06ac22770af9bd0dac2d9925e039b96a8203ad7640df312cecdc221' 
  AND token = 'mE88L1kmKxdeYkEX9vcTpn6IkTZY9c81b/bqio/tJWA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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