SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad47390010347adc5c2cbaefb056741e8b9a7bd057e258ccf8f36ef9af75fbce' 
  AND token = 'euGXGoX7/58isZ8FLGYQY8jwFeLs5GKSMoZqsVPpEjo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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