SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5f66e9184ab44f1395fafe1c325ec67861cadb638c81df726092f683d5fc0dd1' 
  AND token = 'T+FhgLLZ3ACX8UhvAlf59xWPXPiohscmudrfGxAVh+o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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