SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b9a9894054ee903ef1188ca7734cf2f8a143939f63eee0703d425085c488954a' 
  AND token = 'ds4LaojMSd4GjOxjBTvKIa78s8wa/9/ciz9VqKhoE7Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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