SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23d1528982f1d3058a51fd844c36a37012d3332aec06100675872ff6cd22d8f7' 
  AND token = 'T94eki+n3m8mtTJNWSZ15tqMQiND60POrdLtv1wy1M0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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