SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc2f309de9a466f2f6407d3b3aced5a489747ced175adfb6d8b62097350a265d' 
  AND token = '8/mFjw+vAJr2Vg0w/hM92/3gRmfgXcmuWFHbu9mGwl4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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