SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '8e8da8d520a30c45a497af4e0d4e71ca49d395f32aeb165ee1c5d0a3c2528526' 
  AND token = 'VsBu7KGpYZcKSMeh92oBj0rYtWmU6/D8yZ7Ae020rHw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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