SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '384202f4a5395583cf8150633ceb53db90dc248e5be09f355e76bcde9a617ee2' 
  AND token = 'fikHqE83RA1CqZuY9X4DBrfebXAqDuBE3WWfaNbCPtY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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