SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '986648f9ac5ca4c0febc9f8b828a9854bfef8ee39d122b4e7f8cb9693e6dbd0c' 
  AND token = 'HucVhhKpPgt9FtL9QpYQN5Ke/MHOOA4TXRARUNmlehk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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