SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aef8d72c91d138073869eb7dd0286efabaea1300ea424ecaab9d8fac3537503b' 
  AND token = 'KtksW8LS+vVscIz79z53VqcacTJ+Z/d6Q2YBXNMfspo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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