SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '5fa818ccebff9383ca7b1169cbc845fb89c2b58bd0cf46c5a9ed28fe855ba1c9' 
  AND token = 'NFMfLXogqoiBVz9DXWAIpXXqwxd0sMMtHX/wKoCV7Mo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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