SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c28480230e864a65c75fd903ec8ff20c45463091b31dca96295e5d2fffbf8a7e' 
  AND token = 'E+M9eaRNfchQjaZfu3wtewvWiVuODQR4HznrXV/ychU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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