SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '724f7cb001983e9c284656e88423db10ddf14b7f93bfeafad9f8e9b8d2e097ea' 
  AND token = 'o9jM0zT3afHLvmmnTuaWoBLgHVQEmGjhaX/Zof5hLT8=' 
  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"
    }
  }
}