SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '42c94d93cbaf95ee96caeecb9ab1ef9ac68d17da2d0974b94f6442d779d6ab5d' 
  AND token = 'FxfVpi6sZI513t5xUb418ENdHGLetSqYv/WdGHsGbOw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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