SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'acb3d339c60bdd519993f79c66123617ea0c81f778287b415d9264c459b91564' 
  AND token = 'EUzo+igWT9APdF/Z905DCPyNHgcg+Grl0H/e0uEJVEQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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