SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd7b7644810ffdbb692aeacb4c7d00b04f4b9eefa885920257ecaf711f5eddc0' 
  AND token = 'qpgi4/QjFxchDIQFxsGE/9HWE4oXYgOSJoFm+pRQRVg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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