SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cccda0b1a12f89bb679b8a88b852bede47ee78bc0d73f24b12a7b59e09926d82' 
  AND token = 'vtRwafPi0HQa8KNULGx81CLtVJVLuCa01pEU1EWHaDM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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