SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '146951b59dbf9dbbade2bd84d7eb833104ba4dbe8370a1ef082d9dd7dbea789d' 
  AND token = 't/6LW7Up9JJV7Zcc7SBg2OzV2dNDiOxZb5RVo1qyjQs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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