SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '940e3e7179782feb435ad5d06b387e0b28e3339f4a74d7448b095376d55bf7a3' 
  AND token = '/O6uvlsR2WzV1IUO1NEhdD1g/r7kiHflvQiRIWNvGTY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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