SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '88ef32159ff82757a2807b8ab5944aa91b59d8ca096695a4fe0b70e49ecfbc00' 
  AND token = 'lXXWNTF0zewci4njFZu51y4LtE2pMkRZfmzJ99ipmgA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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