SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4994a2058588a01c9dea696d3726c0e1cf67d16159d9b8c98b1ae7497835c93b' 
  AND token = 'Q2ettUiQTpCReDTX4OS+pxGkzVqGuCC5MVPBf12bJr0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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