SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b27afbc74e2b077db593690d0013183e75b84dfe51b1253d4a6911318b29d8e9' 
  AND token = 'e3nL9FxQNDbmGJB4lvB5otjhRoBbYI/d3IdCC+scCH8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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