SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f3f04dcb6313ef4a67dcebcef95947803b8487ee3e8bdaf958879da5db57a17' 
  AND token = 'We/1kzWXpOujzOn7axeMB9t5CZAQXfxPxVdK3QUD6wE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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