SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c7b5b816be01b62d8fb1d7beea920cc72163fc32c11db09118e127d4ca879e6' 
  AND token = '1wLkwdTIVvtzHScoQAPvbUNb2uULtFfnzF0IE5wKnOk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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