SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '8fca90296ec54dc0e14b00f7b6fb74378f8a6ae96a8063605ad7c12d84c33bfc' 
  AND token = 'OYcDPhPXI+89IJw4N5uPZ2Fb4aqXp+YmNigznBLpuOA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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