SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aa959782311c5590b5ab47f4fac973b0b8b7944b12a42c46444e65065b9297c2' 
  AND token = 'hxkAMrpIlpQU2a/QNKFGIyqzqLIxXWTXz455fKkGkok=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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