SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '675459f6f81f74330b83a7c559142d6153bff6c4588e54f6d15327192029b685' 
  AND token = 'KpbEvVsJuS47DDP1CdnORDmSKE7VAY1WQJjaRcX/lRQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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