SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9000e06dd3c7ffd1a864cb43a8fa377be8089d5374f49a0e2b454c3855b4745' 
  AND token = 'xiCvLMd10GozDYdyECMFazELD2Yb+quIKBUA/umtRQQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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