SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4d84de98537416ec1b0c691d3813c13fd55e5c8133f964542e98e34feb0da7f3' 
  AND token = 'RimUogWhynxoDfdpewgjcJzBSkQOj4eD/WATQ7Q2jDw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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