SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae06e942091bc679ef796a493ea624227a383f27b6928aa9c3c457b8fef169f2' 
  AND token = 'D/XMkLSbiAJyxfLYOvzgQc3eivus0fxAYGJpZaKdYJM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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