SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '423c37c54a4f410a8fc25f9f3e6af81e9432f580e92fd04a0d42efb05a6f6b5f' 
  AND token = '7AgiVng2Z4qhVAtrdfONUKNJQxSw6sCHO8UPIWrukHk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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