SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e982a5268e630bb9bc1770fd08d723144400a10e653d291812cc5fa477ec00c2' 
  AND token = '3zKFtgxY1Xnrz+BDkgDnl18Zk6JQ3t9r6zBnggrKR8o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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