SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd4bcc5e2df856f8e35239b47bbabeb23a1325e407743d87346567817fe68eabe' 
  AND token = 'ATFuSIk29cYl9VQDqVGXj3RJ9DZKTxPt/WcGSaskqMw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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