SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '663da3494e3cddc24f1db843c99a7396c53484a9a2625656a427350da4a51167' 
  AND token = 'L5CJ3puERLRtEXzZAo+RkiGm5wyh3dJuWlXrwF/CkXM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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