SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e29c92a02f63b419ebb026d4b389dc79388ba754c7f89dc103d2da07222c753' 
  AND token = 'x9bJAWTM/9JCiXyXU3GJ61R1HTj900QU1XpY/yRahSA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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