SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '950fa26d4425b180d27ad6bc82061ca1b0093d96a8cdc36868f5b7fcc5b237bb' 
  AND token = 'AzGnzbkLCA4DlwpsgPK+SoL+U4noJmXYgViRx6NYwUQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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