SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9616b7a0f56e1ebdd1c2ecac3c576ba4b2ee487e252571663b5d9a30771fe35' 
  AND token = '2giFIepxxq+aat0C8lU2LuXoAc3zpFzlkpjDBp7Xxzg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00069

JSON explain

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