SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'ad5825e20109c9162fc90ec86b9859f5d2005917657992e08a73c9d76a877b47' 
  AND token = 'NKSPP3GGP/rBEZVcGaUm8kzME0EU9vhVYph4UnkOTKY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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