SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30e381b49e6a4419df7fea4933d0a117010e8d330b57296bd34a44b04e7df801' 
  AND token = 'rvuDAUF6rUD+UufdsuFhFEw085f90UH5qkL6vhpBAog=' 
  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"
    }
  }
}