SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '86c3c758e7012d5e241c2fd45a5cad38cff6626cb16f41b634b5dc78d4ccb968' 
  AND token = 'aj4Hsd44oRSfqXR5O/zmiukhNYPaBq+5XK9CLOVynj0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}