SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6b81831a53c0693096f19dd166409b53ac183b771b8549b4ee90f30762113ea1' 
  AND token = 'W1VJc6Z+yYDQOSL/uSaEzRm+OQILDgJyg+9xrLugwdo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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