SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '522b54077e5cdb330e0392956a13674ec5aa55c6e4bb74a79aa9c32b39b3ed68' 
  AND token = 'toJ4yrh5YKJfdybZymoNsvIVsfXAfey26QmMSdMes2s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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