SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9560a7e2f2ea0d2cc67515196da88db7a12a336629809e053588bf0e811ad94f' 
  AND token = 'Uh7IOcPraFgQJscgZWK/L8STDKW7BTzbiteNerQGEq8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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