SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3f94bd08fe4e3ff461f366a1dfa420aeebf06133d5295579c4a07e4421d9d0dc' 
  AND token = 'uAS3rOjAbBHEurkE+Aa1ZMgP0z4uRrbKTRUkig38W1o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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