SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'bf186b092a795e4525e47e22511a058c3cf01537cbfab65c9d161f04cb8976f4' 
  AND token = 'S47CMFK7pAtDQlDjOzoOzE2JBHLmFo8e+IF25oc03Fk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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