SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37ceedc63e196ff83bfe97e8094efbd3c3d02727837e76fb96bf6e87579682c1' 
  AND token = 'c8l9Kwspn2DmFl2MPu8/v/uTaZV2SFqzZHiCEs4k3yM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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