SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e27291fa78c676a31547fa9c9dad24ed5f0b74bca14e20df9b6ab7e1291364ac' 
  AND token = 'dIns9vgILte+IsLwBAJgY83mn50+/v3RzhPKXhHLsdg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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