SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8cbf55eb4a5015170c756ecb1c9ee59f46adcd0a474c26dedd0601b6fc1b274c' 
  AND token = 'X2NZMuBl/40XDMmO0K2LB1hxp5ufPGMhhRRzW5FFOX0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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