SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44885720c66e1945bf63b9d15d392d87597a957cbef3b9634ddbbb6a812c6d61' 
  AND token = 'xKK3p9ggmzvo/YSH5BZ7mzuKr7ye0MJD9fPtXBqk1uM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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