SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed04674affcb06282ec46b640c0743cf7273da194dc76d728b84338b8a03c634' 
  AND token = 'CVUmmxqXhuX21hAEZnE/QJ/6IwDZKbZ3JRcPYmNtiaU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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