SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3f42b319c87cc440118b0470d5b43aeb780012a3ac94559e69538cecec69fc58' 
  AND token = 'eRQ149wqRA0cKMPyUG2xuoFqK0NUO1FJKixeAop5KBo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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