SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c94b241edfb1a7d04f08cfaca6a6029b8f1a9d6601bed609043150680c792cbc' 
  AND token = 'cQCzOIO3g7/QlmRsQ8vkiF3P02CpYf7P+5lsKm1AoTA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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