SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '504600bb40222364d08ac69313e3ed5db7fec8966ea69d541ac4e4674b3c70e7' 
  AND token = 'WOaJjPwkk5mmdhR5Y6gBd38MxQC6zJrHEEawuooXtGI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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