SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f4e2ca42926ace8afcdea4c5c0e250546e78a8baa4c031dd6db4c674a2e4de3' 
  AND token = 'rHEHe2Gz0QSGIBVumEBjTdKMhweppozlaVyo6bpzTHQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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