SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c11528d8a2c1139a2ace98756a704079a1cfa817b57844546c969060a75fae45' 
  AND token = 'xvdFCY6Jiekqhb3ozrTnpYDUwQNlrk1kmaIXaUKLH7M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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