SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6fcc766316d21a9b57a4ea24a1bc9635b8a58957929d3713aabaa162e1727180' 
  AND token = '25JaJBuRVjkrdsz4Hj2H/5K3oZhXVJ0lE+C6cvzsAoQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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