SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce83b2aa8d158270fb243ccb17f71ca3191474da0e16a503e043aa10abbe16ea' 
  AND token = 'eAosatoVDOOsJpbXUMSuUxsZ5/9IuXMCDDLUMl8tsWA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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