SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0861f856f420bf73e78feae6bbc5c236c20fc1c6bba908c18c5e30981e089396' 
  AND token = 'uyXdNgys38UXGNYRUqjMI82t7U1bDwev6y69tlmVz48=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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