SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59b82aac9f26ffcb3a5053c26c1c055945f28b13015a399a9ad5d928273fda4c' 
  AND token = 'iOzKrLqKmSrh2oPoQVIL8DlLmiuIKihW4g8pqYDZ56s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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