SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df0a3561f909dfd6a210911e9f20d1ab6e0a8a766653bc623d7e7abb2ec0af69' 
  AND token = 'bOKzVE49avxUUe8VBDi1HWE8QINcegYPE55Ik6LfkfU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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