SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5111395191e966509452e5ec3135391ed1ca692770a4ea38ab43213b3a300060' 
  AND token = 'gmTKROCbiQQ216x+sQNZJSkoBpUHf3EeSnufS9oB7Gg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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