SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '48b73e265304609968d5568bd7782e1248f6e8a18eb4a3311b6c0af185c74a08' 
  AND token = 'v7DY9B/nTDERLT69k9LSZxPte1cHTLpqBiezrypZzxM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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