SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ffe2b7c69bfe687621e1731b11d7d9757ca51fb3f8f4302dba69ecb19b85f45b' 
  AND token = '3Uctzw4IOLztUhWMfnqoJ/o9DjqdM0IULMuNYhV5vGk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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