SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe92853ea07f04982444e64a9892eacfebd93288643d500d0825f1c12aaf13f8' 
  AND token = 'PGmwjQ5EIbCkR/PE4uK508CLhvCqpW5qIaPIk15RF5o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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